Means for mixing and aerating sands or tailings while under treatment by solvents.



No. 639,540. Patented Dec. I9, 1899. w. DUNCAN.

MEANS FOR MIXING AND AEBATING SANDS 0R TAILINGS WHILE UNDER TREATMENTBY.SOLVENTS.

(Application filed June 27, 1899.) .(No Model.) 2 Sheets-Sheet l.

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Patented Dec. I9, 1899.

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MEANS FOR MIXING AND AERATING SANDS 0F TAILINGS WHILE UNDER TREATMENT BYSOLVENTS.

(Application filed June 27, 1899.)

2 Sheets-Sheet 2.

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WILLIAM DUNCAN, OF DAY DAWN RIDGE, CHARTERS TOWERS, QUEENSLAND.

ME NS For MIXING AND AERATING SANDS 0R TAILINGS WHILE UNDER TRQEATMEENTBY SOLVENTS.

SPECIFICATION forming part of Letters Patent No. 639,540, dated December19, 1899.

Application filed June 27, 1899. Serial No. 722,095., (No model.)

T0 at whom it may concern:

Be it known that 1, WILLIAM DUNCAN, engineer, residing at Day DawnRidge, Charters Towers, Queensland, have invented certain new and usefulImprovements in Means for Mixing and Aerating Sands or Tailings Whileunder Treatment by Solvents; and I do hereby declare the following to bea full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

Numerous attempts have from time to time been made to secure thethorough mixing of sands and tailings, including slimes, with thesolvent while under treatment and also to prevent that close packingwhich prevents the percolation of the solvent and wash liquors. For thispurpose vertical vessels with vertical agitators, revolving barrels, andair, steam, and Water jets have been used; but

these means have not been as efficient as they might be.

My invention relates to improved mechanical means for mixing andaerating sands or tailings, by which terms I include slimes, sludges,and concentrates, while under the action of solvents, whereby time issaved and a better extraction is obtained; and it consists of asemicircular vat provided with a revoluble agitator composed of armsarranged helically on a shaft running the length of the vat. At one endof the vat is placed the fast and loose pulleys and gear for slowlyrotating the agitator, while at the opposite end a series of taps areprovided connected to the vat at various heights and to pipes, so thatthe liquor can be drawn off at any desired point and either run directtothe sump or through a filter to the sump.

In order that my invention may be clearly understood, I will nowdescribe it with the aid of the accompanying drawings, of which Figure 1represents a side elevation of the plant. Fig. 2 is one end elevation ofthe same. Fig. 3 is a view of the opposite end, showing decanting-cocks.

A is the vat, made, preferably, of iron or steel, semicircular insection and of any convenient length. It is carriedin aframework ofwood, which framework is extended to carry the drivinggear.

Over the top of the vat A is a shaft B, (having its center somewhatbelow the center of the vat,) carrying wooden arms in metal socketsarranged helically on said shaft. The shaft Bis carried in bearings Oand has on one end the spur-wheel D, into which gears the pinion D onthe counter-shaft B. This shaft 13 also carries the belt-pulleys D Atthe ends of the vat opposite to the gearing I arrange on a diagonal linea number of taps E, (see Fig. 1,) secured to the end plate and connectedto a common discharge-pipe F, which leads direct to the sump; but byshutting the tap G and opening the tap G the liquors may be divertedthrough a filter J, and thence onto the sump.

The sluice K is fitted for discharging the contents of the vat aftertreatment by the ad dition of water.

Although this invention is designed, primarily, for the treatment ofslimes and sludges, it will be understood that it is useful as a mostefficient washer and puddler and can also be used for treating alluvial.For the latter purpose the vat would be divided into compartments, sothat the material could pass from one to the other, and thus permit ofcontinuous treatment.

When Working on slimes or sludges, the following is the most definiteinstructions of the best method to proceed; but it is obvious that thehereinafter-described treatment must be varied to suit the materialunder treatment: The solution is first put into the vat and then theagitator set in motion at the rate of five to twelve revolutions perminute, and While in motion the material to be treated is shoveled intothe vat in an unsoreened condition, the lumps being broken up by theagitator and liquor, and the whole becomes thoroughly intermixed withthe solution. After the full charge of solids has been shoveled in theagitator is kept at work for such time as is necessary for the solventto act and eventually stopped to allow the contents to settle. The clearliquor is drawn off through the taps E and pipes connected therewith. Aweak wash or, if preferred, a water wash is added and the agitatorrevolved again for a short time. The contents are allowed to settle, theclear liquor being again drawn off,

and this operation repeated until the solvent and its contents areWashed out completely. To empty the vat after the last Wash has beendrained off, Water is added, the agitator set in motion, and the sluiceK opened, so that water and slimes are discharged together, the shaftbeing kept in motion until all is discharged. The gold in the solutionis then recovered by any of the Well-known means.

The bottom of the vat may be perforated and provided with an outer case,so that the contents may in some cases be leached, as in an ordinaryvat, after agitation.

What I claim as my invention, and desire to secure by Letters Patent, is

The herein-described improved means for mixing and aerating sands,tailings, and the like, comprising a semicircular vat, a horizontalrotatable shaft journaled therein, arms helically arranged on saidshaft, said arms depending into close proximity to the bottom, aplurality of outlets arranged at varying levels and unitingin a commonpipe leading to the sump,a cock in said pipe and an independent pipcleading from said discharge-pipe to a filter and having a cock and adischargesluice for draining said vat, substantially as described.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

\VILLIAM DUN CAN.

Witnesses:

A. S. Gnosn, Gno. H. BRITTAIN.

